<?php
namespace DayTidy\HelpSupport;

use DayTidy\Config;
use DayTidy\Data\Gateways;
use DayTidy\Db;
use DayTidy\Db\CreateTables;
use DayTidy\Modules;
use DayTidy\Modules\Base as BaseModule;
use DayTidy\Options\Payment;
use DayTidy\Plugin\Hooks;
use DayTidy\Plugin\Profile;
use DayTidy\Plugin\Requirements;
use DayTidy\Posts\Notification;
use Throwable;

class Diagnostics
{
    private ?string $asset_base_path;

    public function __construct(?string $asset_base_path = null)
    {
        $this->asset_base_path = $asset_base_path;
    }

    /**
     * @return array<string, array<string, mixed>>
     */
    public function sections(): array
    {
        $sections = [
            'environment' => $this->environmentSection(),
            'daytidy' => $this->daytidySection(),
            'database' => $this->databaseSection(),
            'cron' => $this->cronSection(),
            'notifications' => $this->notificationsSection(),
            'payments' => $this->paymentsSection(),
            'assets' => $this->assetsSection(),
        ];

        return apply_filters('DayTidy/F__DayTidy/HelpSupport/Diagnostics__sections/sections', $sections);
    }

    /**
     * @param array<string, array<string, mixed>>|null $sections
     * @return array<int, array<string, string>>
     */
    public function warnings(?array $sections = null): array
    {
        $sections = $sections ?: $this->sections();
        $warnings = [];

        foreach ($sections as $section)
        {
            foreach ((array) ($section['rows'] ?? []) as $row)
            {
                if (($row['status'] ?? 'ok') !== 'warning') continue;

                $warnings[] = [
                    'label' => (string) ($row['label'] ?? ''),
                    'message' => (string) ($row['message'] ?? $row['value'] ?? ''),
                ];
            }
        }

        return apply_filters('DayTidy/F__DayTidy/HelpSupport/Diagnostics__warnings/warnings', $warnings, $sections);
    }

    /**
     * @param array<string, array<string, mixed>>|null $sections
     * @param array<int, array<string, string>>|null $warnings
     */
    public function debugInfo(?array $sections = null, ?array $warnings = null): string
    {
        $sections = $sections ?: $this->sections();
        $warnings = $warnings ?: $this->warnings($sections);

        $data = [
            'generated_at_utc' => gmdate('Y-m-d H:i:s'),
            'warning_count' => count($warnings),
            'warnings' => $warnings,
            'sections' => $sections,
        ];

        return (string) wp_json_encode($this->redact($data), JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES);
    }

    /**
     * @param array<string, array<string, mixed>>|null $sections
     * @param array<int, array<string, string>>|null $warnings
     */
    public function siteSummary(?array $sections = null, ?array $warnings = null): string
    {
        $sections = $sections ?: $this->sections();
        $warnings = $warnings ?: $this->warnings($sections);
        $environment = $sections['environment']['rows'] ?? [];
        $daytidy = $sections['daytidy']['rows'] ?? [];

        return implode("\n", [
            'DayTidy Support Summary',
            'Warnings: ' . count($warnings),
            'WordPress: ' . $this->rowValue($environment, 'wordpress_version'),
            'PHP: ' . $this->rowValue($environment, 'php_version'),
            'DayTidy: ' . $this->rowValue($daytidy, 'daytidy_version'),
            'Site timezone: ' . $this->rowValue($environment, 'timezone'),
        ]);
    }

    /**
     * @param mixed $value
     * @return mixed
     */
    public function redact($value, string $key = '')
    {
        if ($key && preg_match('/(secret|password|passwd|token|nonce|salt|authorization|private|credential|api[_-]?key|client[_-]?secret)/i', $key))
        {
            return '[redacted]';
        }

        if (is_array($value))
        {
            $redacted = [];

            foreach ($value as $item_key => $item_value)
            {
                $redacted[$item_key] = $this->redact($item_value, (string) $item_key);
            }

            return $redacted;
        }

        if (is_string($value))
        {
            return preg_replace('/(sk|pk|whsec|rk)_[A-Za-z0-9_\\-]+/', '$1_[redacted]', $value);
        }

        return $value;
    }

    /**
     * @return array<string, mixed>
     */
    private function environmentSection(): array
    {
        global $wpdb;

        $wp_version = function_exists('get_bloginfo') ? (string) get_bloginfo('version') : '';
        $php_warning = version_compare(PHP_VERSION, Requirements::$PHP, '<');
        $wp_warning = $wp_version && version_compare($wp_version, Requirements::$WP, '<');

        return [
            'label' => __('Environment', 'daytidy'),
            'rows' => [
                // translators: Placeholder values.
                $this->row('wordpress_version', __('WordPress version', 'daytidy'), $wp_version, $wp_warning ? 'warning' : 'ok', $wp_warning ? sprintf(__('DayTidy requires WordPress %s or higher.', 'daytidy'), Requirements::$WP) : ''),
                // translators: Placeholder values.
                $this->row('php_version', __('PHP version', 'daytidy'), PHP_VERSION, $php_warning ? 'warning' : 'ok', $php_warning ? sprintf(__('DayTidy requires PHP %s or higher.', 'daytidy'), Requirements::$PHP) : ''),
                $this->row('mysql_version', __('MySQL version', 'daytidy'), is_object($wpdb) && method_exists($wpdb, 'db_version') ? (string) $wpdb->db_version() : __('Unavailable', 'daytidy')),
                $this->row('server_software', __('Server software', 'daytidy'), isset($_SERVER['SERVER_SOFTWARE']) ? sanitize_text_field(wp_unslash((string) $_SERVER['SERVER_SOFTWARE'])) : __('Unavailable', 'daytidy')),
                $this->row('multisite', __('Multisite', 'daytidy'), function_exists('is_multisite') && is_multisite() ? __('Yes', 'daytidy') : __('No', 'daytidy')),
                $this->row('timezone', __('Timezone', 'daytidy'), function_exists('wp_timezone_string') ? wp_timezone_string() : (string) ini_get('date.timezone')),
                $this->row('permalink_structure', __('Permalink structure', 'daytidy'), function_exists('get_option') ? ((string) get_option('permalink_structure', '') ?: __('Plain', 'daytidy')) : ''),
                $this->row('wp_cron', __('WP-Cron', 'daytidy'), defined('DISABLE_WP_CRON') && DISABLE_WP_CRON ? __('Disabled', 'daytidy') : __('Enabled', 'daytidy'), defined('DISABLE_WP_CRON') && DISABLE_WP_CRON ? 'warning' : 'ok', defined('DISABLE_WP_CRON') && DISABLE_WP_CRON ? __('DayTidy scheduled tasks need an external cron when WP-Cron is disabled.', 'daytidy') : ''),
                $this->row('wp_debug', __('WP_DEBUG', 'daytidy'), defined('WP_DEBUG') && WP_DEBUG ? __('Enabled', 'daytidy') : __('Disabled', 'daytidy')),
            ],
        ];
    }

    /**
     * @return array<string, mixed>
     */
    private function daytidySection(): array
    {
        $profile = Profile::getInstance();
        $plugins = $this->plugins();
        $active_plugins = (array) get_option('active_plugins', []);
        $daytidy_plugins = [];

        foreach ($active_plugins as $plugin_file)
        {
            if (strpos((string) $plugin_file, 'daytidy') === false) continue;

            $plugin = $plugins[$plugin_file] ?? [];
            $daytidy_plugins[] = sprintf(
                '%s %s',
                $this->displayText((string) ($plugin['Name'] ?? $plugin_file)),
                (string) ($plugin['Version'] ?? '')
            );
        }

        $theme = function_exists('wp_get_theme') ? wp_get_theme() : null;
        $module_values = [];
        $config = Config::modules();

        foreach (Modules::get() as $module)
        {
            if (!$module instanceof BaseModule) continue;

            $module_values[] = sprintf(
                '%s: %s',
                $module->key,
                $module->enabled($config) ? __('enabled', 'daytidy') : __('disabled', 'daytidy')
            );
        }

        return [
            'label' => __('DayTidy', 'daytidy'),
            'rows' => [
                $this->row('daytidy_version', __('DayTidy version', 'daytidy'), $profile->version()),
                $this->row('active_theme', __('Active theme', 'daytidy'), $theme ? $this->displayText((string) $theme->get('Name')) . ' ' . $this->displayText((string) $theme->get('Version')) : __('Unavailable', 'daytidy')),
                $this->row('daytidy_plugins', __('DayTidy plugins', 'daytidy'), $daytidy_plugins ? implode(', ', $daytidy_plugins) : __('None detected', 'daytidy')),
                $this->row('modules', __('Modules', 'daytidy'), $module_values ? implode(', ', $module_values) : __('No modules detected', 'daytidy')),
            ],
        ];
    }

    /**
     * @return array<string, mixed>
     */
    private function databaseSection(): array
    {
        try
        {
            $db = new Db();
            $missing = [];

            foreach (CreateTables::tables() as $table)
            {
                $name = $db->table($table);
                $found = $db->getVar($db->prepare('SHOW TABLES LIKE %s', $name));

                if ($found !== $name) $missing[] = $table;
            }

            return [
                'label' => __('Database', 'daytidy'),
                'rows' => [
                    $this->row(
                        'tables',
                        __('DayTidy tables', 'daytidy'),
                        sprintf('%d / %d', count(CreateTables::tables()) - count($missing), count(CreateTables::tables())),
                        count($missing) ? 'warning' : 'ok',
                        count($missing) ? sprintf(
                            /* translators: %s: Comma-separated list of missing DayTidy database tables. */
                            __('Missing tables: %s', 'daytidy'),
                            implode(', ', $missing)
                        ) : ''
                    ),
                ],
            ];
        }
        catch (Throwable $exception)
        {
            return [
                'label' => __('Database', 'daytidy'),
                'rows' => [
                    $this->row('database_status', __('Database status', 'daytidy'), __('Unavailable', 'daytidy'), 'warning', $exception->getMessage()),
                ],
            ];
        }
    }

    /**
     * @return array<string, mixed>
     */
    private function cronSection(): array
    {
        $rows = [];

        foreach (Hooks::crons() as $hook => $recurrence)
        {
            $next = wp_next_scheduled($hook);
            $rows[] = $this->row(
                'cron_' . sanitize_key((string) $hook),
                (string) $hook,
                $next ? sprintf('%s (%s)', gmdate('Y-m-d H:i:s', (int) $next), $recurrence) : __('Missing', 'daytidy'),
                $next ? 'ok' : 'warning',
                $next ? '' : __('This DayTidy scheduled task is not currently scheduled.', 'daytidy')
            );
        }

        return [
            'label' => __('Cron', 'daytidy'),
            'rows' => $rows,
        ];
    }

    /**
     * @return array<string, mixed>
     */
    private function notificationsSection(): array
    {
        $enabled = Modules::enabled('notifications/core');
        $counts = function_exists('wp_count_posts') ? wp_count_posts(Notification::PT) : null;
        $published = $counts && isset($counts->publish) ? (int) $counts->publish : 0;
        $disabled = $this->notificationCountByEnabled(false);
        $enabled_count = $this->notificationCountByEnabled(true);

        return [
            'label' => __('Notifications', 'daytidy'),
            'rows' => [
                $this->row('notifications_module', __('Notifications module', 'daytidy'), $enabled ? __('Enabled', 'daytidy') : __('Disabled', 'daytidy')),
                $this->row('notification_templates', __('Published templates', 'daytidy'), (string) $published),
                $this->row('enabled_notifications', __('Enabled email notifications', 'daytidy'), (string) $enabled_count, $enabled && $published > 0 && $enabled_count === 0 ? 'warning' : 'ok', $enabled && $published > 0 && $enabled_count === 0 ? __('Notification templates exist, but none are enabled.', 'daytidy') : ''),
                $this->row('disabled_notifications', __('Disabled email notifications', 'daytidy'), (string) $disabled),
                $this->row('email_delivery', __('Email delivery', 'daytidy'), __('Uses wp_mail and host/mail plugin configuration.', 'daytidy')),
            ],
        ];
    }

    /**
     * @return array<string, mixed>
     */
    private function paymentsSection(): array
    {
        $options = (new Payment())->get();
        $gateways = Gateways::all();
        $rows = [
            $this->row('payment_method', __('Payment method', 'daytidy'), (string) ($options['method'] ?? 'woo')),
        ];

        foreach ($gateways as $gateway)
        {
            $gateway_options = $gateway->options();
            $missing = $this->missingGatewayFields($gateway->key(), $gateway_options);
            $enabled = !empty($gateway_options['status']);
            $message = $enabled && $missing
                // translators: Placeholder values.
                ? sprintf(__('Missing required configuration: %s', 'daytidy'), implode(', ', $missing))
                : '';

            $value = $enabled ? __('Enabled', 'daytidy') : __('Disabled', 'daytidy');
            if (isset($gateway_options['mode']) && is_scalar($gateway_options['mode']))
            {
                $value .= ' (' . sanitize_text_field((string) $gateway_options['mode']) . ')';
            }

            $rows[] = $this->row(
                'gateway_' . sanitize_key($gateway->key()),
                $gateway->title(),
                $value,
                $enabled && $missing ? 'warning' : 'ok',
                $message
            );
        }

        return [
            'label' => __('Payments', 'daytidy'),
            'rows' => $rows,
        ];
    }

    /**
     * @return array<string, mixed>
     */
    private function assetsSection(): array
    {
        $profile = Profile::getInstance();
        $assets = [
            'dist/js/backend.min.js',
            'dist/js/frontend.min.js',
            'dist/css/backend.css',
            'dist/css/frontend.css',
        ];
        $rows = [
            $this->row('asset_version', __('Asset version', 'daytidy'), $profile->version()),
        ];

        foreach ($assets as $asset)
        {
            $exists = file_exists($this->assetBasePath() . '/' . $asset);
            $rows[] = $this->row(
                'asset_' . sanitize_key(str_replace(['/', '.'], '_', $asset)),
                $asset,
                $exists ? __('Present', 'daytidy') : __('Missing', 'daytidy'),
                $exists ? 'ok' : 'warning',
                $exists ? '' : __('Expected built asset file was not found.', 'daytidy')
            );
        }

        return [
            'label' => __('Assets', 'daytidy'),
            'rows' => $rows,
        ];
    }

    /**
     * @return array<string, mixed>
     */
    private function row(string $key, string $label, string $value, string $status = 'ok', string $message = ''): array
    {
        return [
            'key' => $key,
            'label' => $label,
            'value' => $value,
            'status' => $status,
            'message' => $message,
        ];
    }

    /**
     * @param array<int, array<string, mixed>> $rows
     */
    private function rowValue(array $rows, string $key): string
    {
        foreach ($rows as $row)
        {
            if (($row['key'] ?? '') === $key) return (string) ($row['value'] ?? '');
        }

        return '';
    }

    private function displayText(string $value): string
    {
        if (function_exists('wp_specialchars_decode')) return wp_specialchars_decode($value, ENT_QUOTES);

        return html_entity_decode($value, ENT_QUOTES, 'UTF-8');
    }

    /**
     * @return array<string, array<string, string>>
     */
    private function plugins(): array
    {
        if (!function_exists('get_plugins') && defined('ABSPATH') && file_exists(ABSPATH . 'wp-admin/includes/plugin.php'))
        {
            require_once ABSPATH . 'wp-admin/includes/plugin.php';
        }

        return function_exists('get_plugins') ? get_plugins() : [];
    }

    /**
     * @param array<string, mixed> $options
     * @return string[]
     */
    private function missingGatewayFields(string $gateway, array $options): array
    {
        $fields = [
            Gateways::STRIPE => ['public-key', 'secret-key'],
            Gateways::PAYPAL_STANDARD => ['client-id', 'secret'],
        ];

        $missing = [];
        foreach ($fields[$gateway] ?? [] as $field)
        {
            if (isset($options[$field]) && trim((string) $options[$field]) !== '') continue;

            $missing[] = $field;
        }

        return $missing;
    }

    private function notificationCountByEnabled(bool $enabled): int
    {
        if (!function_exists('get_posts')) return 0;

        return count(get_posts([
            'post_type' => Notification::PT,
            'post_status' => 'publish',
            'fields' => 'ids',
            'posts_per_page' => -1,
            'meta_query' => [
                [
                    'key' => 'daytidy_notification_enabled',
                    'value' => $enabled ? '1' : '0',
                ],
            ],
        ]));
    }

    private function assetBasePath(): string
    {
        if ($this->asset_base_path !== null) return rtrim($this->asset_base_path, '/');

        return rtrim(Profile::getInstance()->path() . '/assets', '/');
    }
}